US4347440A - Filter arrangement for an x-ray apparatus - Google Patents

Filter arrangement for an x-ray apparatus Download PDF

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Publication number
US4347440A
US4347440A US06/166,805 US16680580A US4347440A US 4347440 A US4347440 A US 4347440A US 16680580 A US16680580 A US 16680580A US 4347440 A US4347440 A US 4347440A
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United States
Prior art keywords
filter plate
rays
filter
arrangement according
filter arrangement
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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US06/166,805
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English (en)
Inventor
Werner Haas
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Siemens Medical Solutions USA Inc
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Siemens Medical Laboratories Inc
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Publication date
Application filed by Siemens Medical Laboratories Inc filed Critical Siemens Medical Laboratories Inc
Priority to US06/166,805 priority Critical patent/US4347440A/en
Priority to EP81104863A priority patent/EP0043497B1/fr
Priority to DE8181104863T priority patent/DE3172328D1/de
Priority to CA000381311A priority patent/CA1167983A/fr
Application granted granted Critical
Publication of US4347440A publication Critical patent/US4347440A/en
Anticipated expiration legal-status Critical
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    • G—PHYSICS
    • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
    • G21K—TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES
    • G21K1/00—Arrangements for handling particles or ionising radiation, e.g. focusing or moderating
    • G21K1/10—Scattering devices; Absorbing devices; Ionising radiation filters

Definitions

  • This invention relates to a filter arrangement for an X-ray apparatus having an X-ray source for directing X-rays onto a target, and having a filter plate positioned in said X-rays for attenuation of said X-rays before their impingement on the target. More particularly, this invention relates to a filter arrangement for an X-ray apparatus which is determined for radiation therapy and which directs diverging X-rays onto a human body. Still more particularly, this invention relates to a filter arrangement for a linear accelerator.
  • X-rays having such an oblique local intensity distribution are used, for instance, in radiation therapy. They are applied to certain locations of disease. Deep seats of disease require a high X-ray intensity, whereas higher seats require less intensity to be applied to the body.
  • wedge filters are used to obtain X-rays having an oblique intensity distribution. These filters are inserted into the radiation path between the X-ray source and the target. To each wedge filter belongs a predetermined energy distribution. According to the wedge angle of the filter plates, different oblique intensity distributions are obtained.
  • the doctor or radiologist can apply the X-ray intensity profile which is well adjusted to the location of the disease under treatment, he must dispose of a plurality of wedge filters having various wedge angles. Therefore, a multitude of wedge filters must be at hand and stored.
  • wedge filters have to be changed when another patient undergoes treatment, which procedure requires some time.
  • wedge filters having definite, selected wedge angles are available. Wedge angles which may be necessary for irradiation and which lie between the selected wedge angles of the available wedge filters, cannot be used for treatment.
  • An object of this invention is to provide a filter arrangement for an X-ray apparatus which allows for applying various X-ray intensity profiles on a target, but which requires only one filter plate for this purpose.
  • Another object of this invention is to provide a filter arrangement for an X-ray apparatus which allows for a multitude of oblique intensity distribution settings, but which requires a reduced number of filter plates to be kept in stock.
  • a filter arrangement for an X-ray apparatus has an X-ray source for directing X-rays to a target and a filter plate positioned in the X-ray path for attenuation of the X-rays before impinging on the target.
  • the X-rays from the X-ray source define a center beam axis.
  • the filter plate is pivotly mounted on a pivoting axis which is non-parallel to the center beam axis.
  • the filter plate may be rotated about the pivoting axis to obtain a selected pivoting position. According to the selected position of the filter plate, a selected radiation profile of X-rays transmitted to the target can be obtained.
  • the pivoting axis is preferably positioned remote from and transverse to the center beam axis. It should be noted that the pivoting axis can be arranged as to pass preferably prependicularly through the center beam axis.
  • the filter plate may be a plate having two parallel faces or may be a wedge-shaped plate.
  • the filter plate will be made of a metal which is relatively inexpensive, such as iron or brass.
  • a heavy metal where a high attenuation is desired.
  • a scale showing the pivoting position of the filter plate with respect to a zero position.
  • the scale can be calibrated so that the intensity distribution which corresponds to the selected setting angle of the filter plate can be read directly.
  • FIG. 1 is a schematic view of an X-ray apparatus incorporating a first embodiment of a filter arrangement according to the invention
  • FIG. 2 is a second embodiment of a filter arrangement according to the invention.
  • FIG. 3 is a third embodiment of a filter arrangement according to the invention.
  • FIG. 4 is a diagram showing three intensity distributions which can be obtained by three settings of a filter plate pivotly mounted in the X-ray radiation path, according to the invention.
  • an X-ray apparatus comprises an X-ray point source 2 which emits a bundle 4 of diverging X-rays.
  • the bundle 4, which is defined or limited by a collimator 6, may be of rectangular cross-section.
  • the center beam axis or symmetrical axis is denoted as 8, and two side beams located opposite to each other are denoted as 10 and 12, respectively.
  • the X-rays from the point source 2 pass through a filter plate 14 and impinge on a target 16.
  • the X-ray apparatus illustrated in FIG. 1 is an apparatus for radiation treatment, particularly a linear accelerator, and the target 16 is a part of the human body which contains a seat of a disease.
  • the diseased tissue is supposed to have a depth (measured from the surface of the target 16) varying along an axis x parallel to the surface. This means that the target 16 has to be exposed to an X-ray radiation the intensity of which varies along the axis x.
  • an oblique radiation profile that is an X-ray intensity distribution having an intensity maximum on one side (+x 1 ) of the irradiated skin area and having a intensity slope descreasing slowly towards the other side (-x 1 ) of the irradiated area, has to be applied to the patient.
  • an oblique radiation profile that is an X-ray intensity distribution having an intensity maximum on one side (+x 1 ) of the irradiated skin area and having a intensity slope descreasing slowly towards the other side (-x 1 ) of the irradiated area.
  • the filter plate 14 is a means for adjusting the X-ray energy distribution obtained on the target 16 to a radiation profile which is preselected by the doctor according to the extent, the depth and the nature of the diseased tissue. Adjustment is achieved by selective attenuation of the X-ray radiation.
  • the filter plate 14 is pivotly mounted on a pivoting axis 17 which is positioned remote from and transverse to the center beam axis 8.
  • the pivoting axis 17 is arranged perpendicularly to the center beam axis 8, and the left end of the filter plate 14 is connected to the pivoting axis 17.
  • the filter plate 14 may be of any metal, especially of a light metal or alloy. Brass or iron may be used. Iron (in contrast to brass) will be used when the X-rays have high energies and when a high attenuation is required.
  • the filter plate 14 is a plate that has an upper and a lower face which are parallel to each other. The upper face is exposed to the bundle 4 of the X-rays.
  • the symmetry plane of the filter plate 14 is denoted as 18.
  • the pivoting axis 17 may preferably lie in this plane 18.
  • the filter plate 14 may be rotated about the pivoting axis 17 to achieve preselected setting angles ⁇ .
  • the setting angle ⁇ is measured between the center beam axis 8 and a plane normal to the center beam axis 8.
  • a stationary scale 20 is provided for reading the swivel position or setting angle ⁇ of the filter plate 14. This scale 20 may be calibrated in terms of the X-ray intensity distribution on the target 16.
  • a stationary block 22 is provided with a thread in which is arranged a screw 24.
  • the tip of the screw 24 engages the outer (right) end of the lower surface of the filter plate 14. Due to its weight, the filter plate 14 will rest in the indicated position enclosing an angle ⁇ with a plane perpendicular to the center beam axis 8.
  • the minimum setting angle may be about 15° when a filter plate 14 is used that has parallel faces.
  • the filter plate 14 can be pivoted or rotated continuously about the pivoting axis 17 between the minimum or lowest setting angle, where the plate 14 engages the block 22, and the maximum or upper setting angle, where the screw 24 is completely screwed into the block 22. Any angle between the minimum and the maximum setting angle can be set.
  • the screw 24 (working together with the gravity force of the filter plate 14) can be considered as a means for locking the filter plate 14 in the selected setting angle ⁇ between the two extreme setting angles.
  • the two extreme setting angles determine the setting range of the filter plate 14. This range may be smaller than 45°, particularly smaller than 25°.
  • the filter plate 14 in the whole setting range the upper face of the filter plate 14 is always exposed to the X-rays coming from the X-ray source 2. In other words, in each of a multitude of selectable positions, the filter plate 14 is located in the X-ray radiation path. In the whole setting range, all X-rays emitted from the source 2 and passing the collimator 6 have to go through the filter plate 14.
  • FIG. 2 is illustrated another embodiment of the filter plate 14.
  • This filter plate 14 has two faces which enclose a certain wedge angle ⁇ between each other.
  • the filter plate 14 is a wedge-shaped plate.
  • the wedge angle ⁇ can be chosen such that the minimum setting angle (where still a uniform intensity distribution prevails) can be zero.
  • the symmetry plane 8 of the filter plate 14 passes through the pivoting axis 17.
  • the pivoting axis 17 is again arranged perpendicularly to the center beam axis 8.
  • the upper face of the filter plate 14 is exposed to the X-rays, when the filter plate 14 is positioned under any preselectable setting angle ⁇ , which is between a lower setting angle and an upper setting angle.
  • the wedge-shaped filter plate 14 has a front part, which is of smaller thickness, and a rear part, which is of larger thickness.
  • the pivoting axis 17 is arranged to pass through the rear part.
  • FIG. 3 another embodiment of the filter plate 14 is illustrated, which is also wedge-shaped. However, in this embodiment the pivoting axis 17 passes through the thinner front part of the filter plate 14. Again, the symmetry plane 18 passes through the pivoting axis 16.
  • the filter arrangement of FIG. 3 will generate an intensity distribution on the target 16 which is different from the intensity distribution of the filter arrangement illustrated in FIG. 2. It should be noted that in FIG. 2 the beam 10 will be more attenuated than the beam 12, whereas in FIG. 3 the beam 10 will be less attenuated than the beam 12.
  • one face of the filter plate 14 may be plane, whereas the other one is curved.
  • the shape depends on the X-ray radiation profile which is desired. Generally speaking, the shape of the filter plate 14 should be optimized with regard to the radiation profile to be obtained on the target 16.
  • the X-ray source 2 will generate a uniform intensity distribution I(x) on the target 16 if the filter plate 14 is not present, see curve a.
  • oblique intensity distributions may be used in radiation therapy.
  • tissue of the human body there can be found locations of disease (e.g. a tumor which extends into various depths) which require X-ray irradiations with X-rays having an oblique intensity distribution as shown by curves b and c in FIG. 4.
  • FIG. 4 represents only some arbitrarily chosen intensity distributions.
  • the actual intensity distribution of the X-rays impinging on the target 16 depends on the shape and the material of the filter plate 14 as well as one the setting angle ⁇ . By chosing a proper setting angle ⁇ , a preselected intensity distribution can be obtained on the surface of the target 16.

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  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Apparatus For Radiation Diagnosis (AREA)
  • Radiation-Therapy Devices (AREA)
US06/166,805 1980-07-09 1980-07-09 Filter arrangement for an x-ray apparatus Expired - Lifetime US4347440A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US06/166,805 US4347440A (en) 1980-07-09 1980-07-09 Filter arrangement for an x-ray apparatus
EP81104863A EP0043497B1 (fr) 1980-07-09 1981-06-23 Appareil à rayons X pourvu d'une plaque de filtre
DE8181104863T DE3172328D1 (en) 1980-07-09 1981-06-23 X-ray apparatus comprising a filter plate
CA000381311A CA1167983A (fr) 1980-07-09 1981-07-08 Filtre pour appareil de radiographie

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US06/166,805 US4347440A (en) 1980-07-09 1980-07-09 Filter arrangement for an x-ray apparatus

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US4347440A true US4347440A (en) 1982-08-31

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EP (1) EP0043497B1 (fr)
CA (1) CA1167983A (fr)
DE (1) DE3172328D1 (fr)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4497062A (en) * 1983-06-06 1985-01-29 Wisconsin Alumni Research Foundation Digitally controlled X-ray beam attenuation method and apparatus
US4518869A (en) * 1982-12-21 1985-05-21 Motorola, Inc. Resistance comparator for switch detection
US4641336A (en) * 1983-01-07 1987-02-03 Instrumentarium Corp. Filter arrangement for soft tissue
US4672648A (en) * 1985-10-25 1987-06-09 Picker International, Inc. Apparatus and method for radiation attenuation
US4905268A (en) * 1985-10-25 1990-02-27 Picker International, Inc. Adjustable off-focal aperture for x-ray tubes
US5063298A (en) * 1990-06-15 1991-11-05 Matsushita Electric Corporation Of America Irradiator for dosimeter badges
US5081660A (en) * 1990-06-06 1992-01-14 Yokio Fujisaki High resolution x-ray imaging system with energy fluctuation restricting filters
US5440133A (en) * 1993-07-02 1995-08-08 Loma Linda University Medical Center Charged particle beam scattering system
US5454023A (en) * 1993-06-15 1995-09-26 Planmeca Oy Soft-tissue filter apparatus for a cephalostat
US6369381B1 (en) 1999-01-29 2002-04-09 Troxler Electronic Laboratories, Inc. Apparatus and method for calibration of nuclear gauges
FR2850789A1 (fr) * 2003-01-30 2004-08-06 Ge Med Sys Global Tech Co Llc Tube a rayon x avec filtrage ameliore
US20060062353A1 (en) * 2004-09-21 2006-03-23 General Electric Company System and method for an adaptive morphology x-ray bean in an x-ray system
US20060182226A1 (en) * 2005-02-17 2006-08-17 Ge Medical Systems Global Technology Company, Llc Filter and X-ray imaging device
US20070076851A1 (en) * 2005-09-30 2007-04-05 Pellegrino Anthony J Radiation therapy system featuring rotatable filter assembly
US20080279337A1 (en) * 2007-05-11 2008-11-13 Ping Yuan Filter unit, x-ray tube unit, and x-ray imaging system
US20100054420A1 (en) * 2008-08-29 2010-03-04 Ping Yuan Adjusting device for barrier blade of scattered x-ray
US20100246775A1 (en) * 2009-03-31 2010-09-30 Ping Yuan Filter and x-ray imaging apparatus using the filter
US8189889B2 (en) 2008-02-22 2012-05-29 Loma Linda University Medical Center Systems and methods for characterizing spatial distortion in 3D imaging systems
CN111436194A (zh) * 2018-11-13 2020-07-21 西安大医集团股份有限公司 滤光器、放射线扫描装置及放射线扫描方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4528685A (en) * 1983-05-16 1985-07-09 General Electric Company X-ray beam filter device

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB966877A (fr) *
US2405444A (en) * 1942-08-05 1946-08-06 Moreau Santiago Radiographic filter
US2506342A (en) * 1947-08-09 1950-05-02 Arnold C Burke Placenta filter
US3248547A (en) * 1963-10-21 1966-04-26 Picker X Ray Corp Device for accurately positioning X-ray filters in the beam path
US3631249A (en) * 1968-10-03 1971-12-28 Siemens Ag Adjustment apparatus for x-ray wedge filter plates
DE2053089A1 (de) * 1970-10-29 1972-05-04 Siemens Ag Strahlenblende für Röntgenstrahlen
US3748487A (en) * 1970-02-09 1973-07-24 Medinova Ab Radiation absorbing device for radiographic apparatuses
US3917954A (en) * 1973-11-09 1975-11-04 Gundersen Clinic Ltd External x-ray beam flattening filter

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH243731A (de) * 1947-03-13 1946-07-31 H Imfeld Röntgenapparat mit einem die Röntgenstrahlen schwächenden Filter.

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB966877A (fr) *
US2405444A (en) * 1942-08-05 1946-08-06 Moreau Santiago Radiographic filter
US2506342A (en) * 1947-08-09 1950-05-02 Arnold C Burke Placenta filter
US3248547A (en) * 1963-10-21 1966-04-26 Picker X Ray Corp Device for accurately positioning X-ray filters in the beam path
US3631249A (en) * 1968-10-03 1971-12-28 Siemens Ag Adjustment apparatus for x-ray wedge filter plates
US3748487A (en) * 1970-02-09 1973-07-24 Medinova Ab Radiation absorbing device for radiographic apparatuses
DE2053089A1 (de) * 1970-10-29 1972-05-04 Siemens Ag Strahlenblende für Röntgenstrahlen
US3917954A (en) * 1973-11-09 1975-11-04 Gundersen Clinic Ltd External x-ray beam flattening filter

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Kijewski, Chin and Bjangard, "Wedge-shaped dose distributions by computer-controlled collimator motion", Medical Physics, vol. 5, No. 5, Sep./Oct. 1978, pp. 426-429. *

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4518869A (en) * 1982-12-21 1985-05-21 Motorola, Inc. Resistance comparator for switch detection
US4641336A (en) * 1983-01-07 1987-02-03 Instrumentarium Corp. Filter arrangement for soft tissue
US4497062A (en) * 1983-06-06 1985-01-29 Wisconsin Alumni Research Foundation Digitally controlled X-ray beam attenuation method and apparatus
US4672648A (en) * 1985-10-25 1987-06-09 Picker International, Inc. Apparatus and method for radiation attenuation
US4905268A (en) * 1985-10-25 1990-02-27 Picker International, Inc. Adjustable off-focal aperture for x-ray tubes
US5081660A (en) * 1990-06-06 1992-01-14 Yokio Fujisaki High resolution x-ray imaging system with energy fluctuation restricting filters
US5063298A (en) * 1990-06-15 1991-11-05 Matsushita Electric Corporation Of America Irradiator for dosimeter badges
US5454023A (en) * 1993-06-15 1995-09-26 Planmeca Oy Soft-tissue filter apparatus for a cephalostat
US5440133A (en) * 1993-07-02 1995-08-08 Loma Linda University Medical Center Charged particle beam scattering system
US6369381B1 (en) 1999-01-29 2002-04-09 Troxler Electronic Laboratories, Inc. Apparatus and method for calibration of nuclear gauges
FR2850789A1 (fr) * 2003-01-30 2004-08-06 Ge Med Sys Global Tech Co Llc Tube a rayon x avec filtrage ameliore
US20040184582A1 (en) * 2003-01-30 2004-09-23 Saladin Jean Pierre Filter system for radiological imaging
US7092490B2 (en) 2003-01-30 2006-08-15 Ge Medical Systems Global Technology Company, Llc Filter system for radiological imaging
US7272208B2 (en) 2004-09-21 2007-09-18 Ge Medical Systems Global Technology Company, Llc System and method for an adaptive morphology x-ray beam in an x-ray system
US20060062353A1 (en) * 2004-09-21 2006-03-23 General Electric Company System and method for an adaptive morphology x-ray bean in an x-ray system
US20060182226A1 (en) * 2005-02-17 2006-08-17 Ge Medical Systems Global Technology Company, Llc Filter and X-ray imaging device
CN1822239B (zh) * 2005-02-17 2010-06-23 Ge医疗系统环球技术有限公司 滤波器和x射线成像设备
US7260183B2 (en) 2005-02-17 2007-08-21 Ge Medical Systems Global Technology Company, Llc Filter and X-ray imaging device
US7263170B2 (en) * 2005-09-30 2007-08-28 Pellegrino Anthony J Radiation therapy system featuring rotatable filter assembly
US20070076851A1 (en) * 2005-09-30 2007-04-05 Pellegrino Anthony J Radiation therapy system featuring rotatable filter assembly
US20080279337A1 (en) * 2007-05-11 2008-11-13 Ping Yuan Filter unit, x-ray tube unit, and x-ray imaging system
US7680249B2 (en) 2007-05-11 2010-03-16 Ge Medical Systems Global Technology Company, Llc Filter unit, X-ray tube unit, and X-ray imaging system
US8189889B2 (en) 2008-02-22 2012-05-29 Loma Linda University Medical Center Systems and methods for characterizing spatial distortion in 3D imaging systems
US8737707B2 (en) 2008-02-22 2014-05-27 Robert D. Pearlstein Systems and methods for characterizing spatial distortion in 3D imaging systems
US9196082B2 (en) 2008-02-22 2015-11-24 Loma Linda University Medical Center Systems and methods for characterizing spatial distortion in 3D imaging systems
US20100054420A1 (en) * 2008-08-29 2010-03-04 Ping Yuan Adjusting device for barrier blade of scattered x-ray
US20100246775A1 (en) * 2009-03-31 2010-09-30 Ping Yuan Filter and x-ray imaging apparatus using the filter
US8184776B2 (en) 2009-03-31 2012-05-22 Ge Medical Systems Global Technology Company, Llc Filter and X-ray imaging apparatus using the filter
CN111436194A (zh) * 2018-11-13 2020-07-21 西安大医集团股份有限公司 滤光器、放射线扫描装置及放射线扫描方法

Also Published As

Publication number Publication date
CA1167983A (fr) 1984-05-22
EP0043497B1 (fr) 1985-09-18
DE3172328D1 (en) 1985-10-24
EP0043497A1 (fr) 1982-01-13

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